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Re: m68k bootstrapping broken


On Wed, Jan 07, 2004 at 09:53:14PM +0100, Bernardo Innocenti wrote:
Hi,

I am now comparing the rtl dumps of the lshrdi example to figure
out where to start debugging. 2 compilers built from identical
source and config, the native one is somewhere miscompiled.

- in *.i.00.cgraph the whole "Final callgraph:" section  is missing in the
  dump generated by the native compiler
- in *.i.01.rtl the first insns are particularly suspect:

--- native/xx.i.01.rtl  2004-01-08 20:35:55.000000000 +0100
+++ xc/xx.i.01.rtl      2004-01-08 21:30:29.000000000 +0100
@@ -5,198 +5,197 @@
 
 (note 2 1 3 NOTE_INSN_DELETED)
 
-(insn 3 2 4 (set (reg:SI 31)
-        (reg/f:SI 25 virtual-incoming-args)) -1 (nil)
-    (nil))
-
-(insn 4 3 5 (set (reg/v:DI 32 [ u ])
-        (mem/f:DI (reg:SI 31) [2 u+0 S8 A16])) -1 (nil)
-    (nil))
+(insn 3 2 4 (set (reg/v:DI 31 [ u ])
+        (mem/f:DI (reg/f:SI 25 virtual-incoming-args) [2 u+0 S8 A16])) -1 (nil)
+    (expr_list:REG_EQUIV (mem/f:DI (reg/f:SI 25 virtual-incoming-args) [2 u+0 S
8 A16])
+        (nil)))
 
-(insn 5 4 6 (set (reg/v:SI 33 [ b ])
-        (mem/f:SI (plus:SI (reg:SI 31)
+(insn 4 3 5 (set (reg/v:SI 32 [ b ])
+        (mem/f:SI (plus:SI (reg/f:SI 25 virtual-incoming-args)
                 (const_int 8 [0x8])) [3 b+0 S4 A16])) -1 (nil)
-    (nil))
+    (expr_list:REG_EQUIV (mem/f:SI (plus:SI (reg/f:SI 25 virtual-incoming-args)
+                (const_int 8 [0x8])) [3 b+0 S4 A16])
+        (nil)))

Where does that difference come from?

Do I need to debug the rtl generation, or even before that?

The above diffs may suggest that something is wrong with the
improved prologue/epilogue generation on m68k but since this
is a miscompiled compiler it could be very easilly pure
coincidence.

Richard


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